I am currently on Truvada (1 450mg daily), Prezista (3 x 300mg daily) and Norvir 100mg. Viral load is undetectable and t cell count at 144 since diagnosed in Dec 2008. My most recent prescription now incorporates the new strength Prezista pills as 400mg of which my doctor now prescribes (2 x 400mg) daily. I am concerned that this dosage now reduces my intake of Duranivir from 900mg to 800mg. Is there a risk of viral replication and resistance from reducing the levels of Prezista (duranivir) in the system from the previous dosage levels? I asked my pharmacist and they just shrugged their shoulders and said there was nothing they could do as this is the new marketed dosage of Prezista...which really doesnt address my concerns. Should i perhaps be taking (2 and 1/2 x the new dose pills to remain on the 900mg which means fiddly pill splitting and what are the complications if any of splitting these pills.?

Thanks for all your great work on this site.

Hello and thanks for your post.

There are two different dosing strategies for darunavir (Prezista)- for persons who are treatment experienced (namely with protease inhibitor resistance), the medication should be dosed 900 mg twice daily with 100 mg ritonavir (Norvir) twice daily.

It appears that you might be on first-line protease treatment. In that case, darunavir can be dosed at 800 mg with 100 mg ritonavir, all once-daily.

Your change in dose had more to do with the relatively new availability of the 400 mg darunavir pill. Before the 400 mg pill, many doctors tried to get close to 800 mg by using the 3x300 mg strategy. Now that the 400 mg pill is available, your pharmacy and doctor appropriately modified your dosing. This shouldn't affect the potency of your regimen.

Be well, BY